A Fats Primer

Confused by all the health info on fats? Learn which ones keep your heart healthy and which ones to avoid.

A Fats Primer

New York City's banning artificial trans fat and other places are on the brink of doing the same—it's safe to say that fat's in the crossfire. With all the jargon, understanding which fats are good can be a challenge. But if you know the right questions, it's easy to understand how fat impacts your health.

The Skinny on Fat

What is trans fat, and why is it bad?

Trans fats, or trans fatty acids, are created when hydrogen is added to liquid vegetable oils, turning them into a solid, which makes the fat last longer and cost less. Trans fat raises your LDL (bad—think “lousy”) cholesterol and may lower your HDL (good—think “healthy”) cholesterol, increasing your risk of stroke and heart disease.

Is trans fat worse than saturated fat?

You should try to limit both trans and saturated fats because they both increase your LDL cholesterol. Trans fat may also decrease your HDL cholesterol, so some experts think it may be slightly worse for you than saturated fat.

How do I know if trans fats are in my food?

Read the ingredient list—if you see "partially hydrogenated," your food has trans fat. The Nutrition Facts label should also list the trans fat grams per serving. Keep in mind, many fried foods and those made with solid shortening or stick margarine typically have trans fat. A small amount of trans fat is also found naturally in some animal products, like cheese and milk.

How much trans fat should I eat a day?

The American Heart Association recommends no more than 1 percent of your calories come from trans fat. On a 2,000-calorie-a-day diet, that equates to a maximum of 20 calories or about 2 g of trans fat per day. Given the amount of trans fat that occurs naturally in some foods, there's virtually no room for adding artificial trans fat.

Be smart about fat

Pick vegetable oils (except for palm kernel and coconut) and margarines in liquid, tub or spray form. The amount of saturated and trans fat is lower in these than in solid shortenings, hard margarines and butter.